Construction of fuselage or other bodies of aircraft



Jan. 10, 1933. w 1,894,011

CONSTRUCTION OF FUSELAGE OR OTHER BODIES OF AIRCRAFT Filed Aug. 15, 1952 4 Sheets-Sheet 1 Jan. 10, 1933. a. N. WALLIS 1,394,011

CONSTRUCTION OF FUSELAGE OR OTHER BODIES 0F AIRCRAFT 4 Sheets-Sheet 2 Filed Aug. 15, 1952 u NQH m/Bu Jan. 10, 1933. B. N. WALLIS 1,394,011

CONSTRUCTION OF FUSELAGE OR OTHER BODIES OF AIRCRAFT Filed Aug. 15. 1932 4 Sheets-Sheet. J

Jan. 10, 1933.

B.- N. WALLIS CONSTRUCTION OF FUSELAGE OR OTHER BODIES 0F AIRCRAFT Filed Aug-- 15, 1932 4 Sheetq-Sheqt A Patented Jan. 10, 1933 UNITED STATES PATENT OFFICE BARNES NEVILLE WALLIS, OF WE'YBRIDGE, ENGLAND, ASSIGNOB TO VICKEBfi (AVIATION) LIMITED, OF WEYBRIDGE, ENGLAND CONSTRUCTION OF FUSELAGE OR OTHER BODIES OF AIRCRAFT Application filed August 15,1932, Serial No. 628,910, and in GreatJBritain August 27, 1931;

In constructin fuselage and other bodies of cylindrical, elliptical and other curved section, a constructor has the choice between making a stressed skin construction or a rectangular or polygonal analytical structure having longitudinal members and diagonal bracing members, the exterior form being secured by formers giving the required rounded contour. In the case of a stressed skin construction, excessive weight is necessary, while in the analytical structure the longitudinals and bracing members make up an interior frame, inscribed within the rounded streamline form, with consequent waste of weight in providing formers and also of valuable space which should be afforded within the fuselage, especially in the case of passenger and troop carrier machines.

The object of this invention is to provide such an analytical, structure in which the waste of valuable space is avoided, and the weight due to formers and/or stressed skin construction is saved.

To achieve these objects it is proposed, ac-

cording to this invention, that the'bracing members, instead of being straight and so reducing the interior space of the structure, are formed with their axes as geodesics in or parallel to the contour which it is desired to secure for the structure, the structure being double or cross braced in every panel. The bowing outwards of single bracing members would involve difliculties due to the endwise compression loads tending to increase the bow of such bracing members and the endwise tension loads tending to decrease the bow of said bracing members; and the provision of outwardly bowed bracing members, themselves designed to resist such endwise com pression and tension stresses would entail considerable increase in weight of such members and would thus rob the analytical structure of its advantages in reducing the weight of the structure as compared with the stressed r skin construction, whose chief disadvantage is the weight entailed. It should, however, be observed that with the disposition of members according to this invention under all torsional and shear forces to which the fuselage is subjected, the compression forces in one or straighten t bracing member tending are equal to the tension member tending to decrease handed bracing e bow,

to increase the bow orces in the opposite so that by securing the halved in each panel,

this device therefore having the effect, according to the wellknown laws connecting a plied lateral forces with the length and the xation of beams, of reducing the bending moment in each portion 0 of each bracing bar to of the value it would approximately 1/12th have if the full length of the bracing bar in each panel were involved.

It is a feature of this invention-that the axis of each bracing member is enabled to retam its shape as a true geodesic in the required surface by constructing it with radial depth in comp its innate radial stiffness efi'ect of the rigidity of mg the forces normal eat arison with its width,

thus simulating the a solid bod in supplyto the osculziting plane which are required to maintain a loaded geodetic string in equilibrium.

The bracing members are preferably made of channel cross-section with the web arranged radial and the flanges arranged parallel to the required surface. In this way, the bowed bracing members may be built very little heavier than in the case where straight diagonal bracing members are employed and the additional space hitherto secured by a tion may, now be secured in an within the fuselage stressed skin construcin accordance with this invention,

analytical structure of considerably less weight than such stressed skin construction, or

rectangular analytical construction, by reason of the omission of the former members.

In a preferred cons truction, the frame of an analytical structure on which the fusela is to built, is constructed of tubular longitudinal members assembled together in bays, each bay comprising lengths of tube terminating in sleeve connections adapted to connect to the adjacent sleeve connections of the neighbouring bay, and adapted also to receive the bracing members for staying the tubes in each section apart and for trans-v mittin and resisting torsional and shear forces in the structure. Such bracing members are constructed to the required curvature to suit the rounded form of the fuselage required, and in each panel of each bay the bracing members cross and intersect each other and are securely connected to each other at the point of intersection.

In assembling the bays together, a bracing member crossing a panel of one bay, becomes continuous with a similar member crossing the diagonally adjacent panel of the next bay, and as these members follow a geodetic line the bracing members when continued from bay to ba constitute a continuous geodesic winding rom one end of the fuselage to the other. In a similar way the second bracing member in the first bay joins with the corresponding bracing member in the adjacent bays and continues in a geodetic "line winding in the opposite hand to the first geodesic from one end of the fuselage to the other.

Fuselages or frames of aircraft have been proposed which are constructed of continuous longitudinal members about which are arranged two series of helically wound laths which intersect on the longitudinal members to which they are secured. In this proposal, however, the longitudinal members were not braced by bracing members which cross between the longitudinal members, while the laths have a much smaller radial depth than width, and, consequently, this, construction if kept within the required limits of weight would be quite unsuitable for receiving the bonding and the torsion loads to which fuselages and the like are subjected.

The invention will now be described with reference to the form of construction illustrated on the accompanying drawings, in which Fig. 1 is a side elevation illustratin the structure as a plied to the tail end 0 the fuselage showing the longitudinal members built up in bays and showing the bracing members, but omitting for clearness the stringers and indicating the fuselage in chain dotted lines.

Fig. 2 is a side elevation of one bay and parts of its adjacent bays drawn to an enarged scale in order to show the construction of the tubular members, bracing members and stringers, the bays having a parallel contour instead of a tapering contour as in Fig. 1.

posed of four tubular booms, only two of which are shown and marked a and (1. These booms are made up in bays marked A, B, C, D and E and are provided at each end of each bay with strengthening sleeves (not shown) by which the booms in one bay are fixed to the corresponding booms in the next adjacent bay. Each bay comprises four panels, two side panels and top and bottom panels. In each of these panels there is arranged bracing members 0, c c 0. One set of these bracing members are arranged in each panel in the construction illustrated and these are repeated in the remaining side panel and in the top and bottom panels. The bracing members are bowed outwardly and are securely connected to each other at the point of intersection by the intersecting fitting marked d and to the tubular members by end fittings marked e.

In the particular construction illustrated and as shown more clearly in Figs. 2-5, the bracing members 0, c and the opposite bracmg members 0', c are divided into separate halves which connect to the member d. Each half bracing member 0 or c or c or c is constructed of channel-shape in cross-section and such half bracing member is formed at one end with an extension 0 of its web which, as shown in Fig. 4, is bent at an angle to its web, so as to fit flat against a plate d extending between two side star-shaped plates d, d which fit against either sides of the flanges, these plates (1, d, d constitutin the intersecting fitting indicated general y by d in Fig. 1. The extensions 0 on opposed half bracing members such as c and c are fixed together by a common rivet d, while the flanges of the half bracin members are also secured to the plates d by rivets d. I The other end of each of these half bracing members has its web cut away and bent inwardly to rovide a part 0', shown in Fig. 5, which ts partly around the exterior of the tubular boom a, to which it is secured by a rivet c. The flanges at thisend of the half bracing member extend one on either side of the tubular boom where they are fixed to the end fittings c carried on the boom. In an alternative construction, one bracing member may be made continuous, the intersecting opposite handed bracin member only being made in halves. The en fittin are constructed'as illustrated in Fig. 5 an comprises a U-shaped member having two parts marked 6, e serving as gusset plates one on either side of the boom. The flanges of the four half bracing members 0 cf, 0, a are secured to the gusset plates by rivets e and the gusset plates are secured by rivets e to the tubular booms, all four of which are shown in Fig. 3 and marked a,

a a and a The middle e of the end fitting is provided with a hole e by which it 5 is seated on the axially extending flange c of the key plate It for connecting the tubular booms together.

Outside the structure thus formed and in order to avoid quilting of the fabric, stringers 19 f are attached in the direction of the length of the booms and around these stringers fabric covering 9, indicated by chain dotted lines in Figs. 1 and 3, may be applied and secured in any convenient manner. Similar stringers 7 may also be attached inside the structure thus formed if required, these stringers f also extending in the direction ofthe length of the booms and to which any suitable material may be applied and secured to form interior walls.

Although a construction has been described and illustrated employing tubular members and web channels, it is clear that any alternative forms of construction, such as lattice braced booms and bracing bars could be employed.

What I claim as my invention and desire to secure by Letters Patent is 1. An aircraft body structure comprising in combination an outside covering, a structure for supporting and shaping the coverin constituted by longitudinal members, opposed bracing members having their exterior borders constitutin geodetic lines in the external contour of tfie structure, said bracing members being of reater radial depth than width, and means or attaching the opposed bracing members to each other where they intersect.

2. An aircraft body structure comprising in combination an outside covering, a structure for supporting and shaping the covering constituted by longitudinal members, opposed bracing members having their exterior borders constituting geodetic lines in the external contour of the structure, each bracing member being constructed in two halves and being of greater radial depth than width, and fittings for securing the halves of the bracing members to each other and to the halves of the opposed bracing members at points of intersection of said bracing members.

3. An aircraft body structure comprising in combination an outside covering, a structure for supporting and shaping the covering constituted by longitudinal members, op-

osed bracing members having their exterior borders constituting geodetic lines in the external contour of the structure, said bracing members being of greater radial depth than Width, gusset plates interconnecting the ends of the bracing members with the longitudinal members, and fittings for securing the bracing members together at their points of intersection.

4. An aircraft body structure comprising in combination an outside covering a structure for supporting and shaping t e covering constituted by longitudinal members, opposed bracing members having their exterior borders constituting geodetic lines in a surface parallel to the external surface of the structure, each bracing member being constructed in two halves and being of greater radial depth than width, gusset plates interconnecting one end of each half bracing member with the longitudinal members, and fittings forsecuring other ends of the halves of each bracing member together and to the halves of the opposed bracing member at their points of intersection.

5. An aircraft body structure comprising in combination an outside covering, a struc'- ture for supporting and shaping the covering constituted by longitudinal members, opposed bracing members intersecting intermediate the longitudinal members having their exterior borders constituting geodetic lines in the external contour of the structure, said opposed bracing members being of greater 99 radial depth than width and being connected together at their points of intersection, and stringers extending across the bracing members parallel to the longitudinal members and serving to connect the outsides of the brac- 95 ing members to the inside surface of the covering.

6. An aircraft body structure comprising in combination an outside coverin interior walls, a structure for supporting and shaping 100 said covering and walls constituted by longitudinal members, opposed bracing members intersecting intermediate the ion 'tudinal members having their exterior bo ers constituting geodetic lines in the external contour of the structure, said opposed bracing members being of greater radial depth than I width and being connected together at their points of intersection, and sets of stringers extending across the bracin members parallel to the longitudinal mem rs and serving respectively to connect the outsides of the bracing members to the inside surface of the covering and the insides of the bracing members to the interior walls of the body structure.

7. An aircraft fuselage comprising an outer fabric covering, a structure for su rgorting and shaping the covering constitute y longitudinal members, channel section opposed bracing members intersecting intermediate the longitudinal members, gusset plates securing the ends of the bracing members to the longitudinal members, and fittings securing the bracing membe s together at their inter- 1 sections, said bracing members having a greater radial depth than width, having their exterior borders forming oedetic lines in the external contour of the uselage, and having their flanges and Webs shaped to fit the longitudinal members and the fittings at their intersections.

8. An aircraft fuselage comprising an outor fabric covering, a structure for supporting andshaping the covering constituted by longitudinal members, channel section bracing members intersecting intermediate the longitudinal members, gusset plates securing the ends of the bracing members to the longitudinal members, and fittings securing the bracing members together at their intersections, said bracing members having a greater radial depth than width, having their exterior borders forming eodetic lines in the external contour of the uselage, and having their flanges and webs shaped to fit the longitudinal members and-the fittings at their inter sections, and stringers extending across the bracing members parallel to the longitudinal members and serving to connect the outsides of the bracing members to the inside surface of the covering.

9. An aircraft fuselage comprising an outer fabric covering, a structure for su rting and shaping the covering constitute b y longitudinal members, channel section opposed bracing members intersecting intermediate the longitudinal members, gusset plates securing the ends of the bracing members to the longitudinal members, and fittings securing the bracing members together at their intersections, one of said bracing members being continuous between the longitudinal members and the opposed bracing member being formed in two halves united together by the fitting at the intersection of the bracing members, all the bracing members having their exterior borders forming eodetic lines in the external contour of the uselage,

" having a greater radial de th than Width,

and having their flanges an webs shaped to fit the longitudinal members and the fittings at their intersections.

10. An aircraft fuselage comprising an outer fabric covering, a structure for supporting and shaping the covering constituted by lon itudinal members, channel section opd racing members intersecting intermediate the longitudinal members, gusset plates securing the ends of the bracing members to the longitudinal members, and fitting securing the bracing members together at their in tersections, said bracing members being made in two halves united together and secured to the halves of the opposed bracing member by the intersecting fitting, all the bracing members having their exterior borders forming geodetic lines in the external contour of the fuselage, having a greater radial depth than width, and having their flanges and webs shaped to fit the longitudinal members and the fittings at their intersections.

In witness whereof I have hereunto set my hand.

BARNES NEVILLE "WALLIS. 

